There is a continuous challenge to design lithium batteries with higher and higher energy densities. Silicon, alone or in combination with other materials such as germanium, tin, antimony and aluminum, has been widely studied as an anode material for lithium batteries. Currently-used graphite anodes have a much lower lithium storage capacity than do silicon anodes. However, silicon expands as much as 400% upon lithiation, which causes problems such as cracking, making it difficult for silicon to endure much cycling. It remains a challenge to exploit the theoretical lithium capacity of silicon in a lithium battery anode.